Mr Calcu | Instantly calculate antenna gain and beamwidth to improve signal accuracy, efficiency, and range in any RF system.

Calculate and optimize antenna gain and beamwidth with precision. Boost performance and master RF design with this powerful, engineer-trusted tool.

Antenna Gain & Beamwidth Calculator

Antenna Gain & Beamwidth Guidelines

You’re just a few inputs away from engineering clarity!

Usage Guidelines

  • Use GHz for frequency and meters for diameter inputs.
  • Efficiency (η) is often 0.5–0.7. A default of 0.65 is typical for clean parabolic reflectors.
  • The beamwidth formula assumes a circular aperture. Elliptical or offset dishes require correction factors.
  • Wavelength is calculated as λ = c / f, where c = 3 × 108 m/s.
  • Beamwidth under 1° demands high mechanical alignment precision.
  • Large antennas at low frequencies may be impractical to build despite narrow beamwidth benefits.

Antenna Gain & Beamwidth Description

What Are Antenna Gain and Beamwidth?

Antenna gain and beamwidth are essential parameters in designing antennas for wireless systems. Together, they determine how focused and directional the signal transmission or reception is.

Antenna Gain

  • Measures how much signal an antenna can direct compared to an isotropic radiator (ideal point source).
  • Higher gain means more focused signal in one direction, improving range and signal strength.
  • Calculated with:
    G = η * (π * D / λ)^2

Beamwidth

  • Defined as the angular width (in degrees) of the main lobe of the radiation pattern.
  • Narrow beamwidths offer high directionality, ideal for long-distance or interference-sensitive applications.
  • Approximated using:
    θ ≈ 70 * (λ / D)

Where:

  • G = Gain (linear, convert to dBi with 10 * log10(G))
  • η = Efficiency (typically 0.5 to 0.7)
  • D = Diameter of the antenna (m)
  • λ = Wavelength (λ = c / f)
  • f = Frequency in Hz
  • c = Speed of light ≈ 3 × 108 m/s

Real-World Mini Case Studies

Case Study 1: Satellite Uplink (14 GHz, 1.2 m dish)

  • Wavelength: λ = 0.0214 m
  • Gain: G ≈ 4691 → G(dBi) ≈ 36.7
  • Beamwidth: ≈ 1.25°
  • Use: Geostationary satellite tracking with minimal adjacent satellite interference.

Case Study 2: Wi-Fi Backhaul (5.8 GHz, 0.3 m dish)

  • Wavelength: λ = 0.0517 m
  • Gain: G ≈ 190 → G(dBi) ≈ 22.8
  • Beamwidth: ≈ 12.05°
  • Use: Point-to-point wireless link between urban buildings with minimal interference.

Get accurate, engineering-grade results in seconds—start optimizing your antenna performance now!

Example Calculation

Example Calculation Table

Frequency (GHz)Diameter (m)Gain (dBi)Beamwidth (°)
2.4120.310.2
5.80.624.16.5
141.236.71.25
100.329.44.1
0.90.515.218.3

Frequently Asked Questions

Antenna gain measures the concentration of signal in a particular direction.

Beamwidth is calculated based on the antenna's diameter and operating frequency using the formula θ ≈ 70 * (λ / D).

Gain increases with frequency for a fixed antenna size, but higher frequencies suffer from atmospheric attenuation and alignment sensitivity.

These formulas apply to circular aperture antennas. Other types like Yagi or horn antennas have different patterns and empirical models.

Real-world losses such as surface roughness, feed spillover, and blockage can reduce effective gain. Check your efficiency assumption.

This tool is not ideal for mobile omnidirectional antennas, which use different models and rarely focus gain directionally.

Beamwidths under 1° are prone to alignment challenges and require stabilized mounts in mobile or satellite applications.

A larger antenna diameter reduces beamwidth, resulting in a more focused signal and improved directionality.

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